Keyboard actuator



` Patented Mar. 5,1940 Y 'PA'rizlslT` ori-lcs KEYBOARD ACTUATOR Albert w. Mins, Endicott, N. Y., assignor to International Business Machines Corporation, New York, N. Y., a corporation of New York Application May 6, 1938, Serial Np. 206,3-15

1 Claim.

'I'his case relates to automatic actuating means for a data transcribing machine, such as a typewriter.

I An object of the invention is to provide simr, plied novel pneumatic actuators for typewriter elements or the like.

The object is still further to provide novel pneumatic means for effecting the coupling oi a power drive to a printing element.l

It is also contemplated to provide a novel arrangement of banks or tiers of -pneumatics for operating the keys of the typewriter or the like. Further objects of the instant invention reside in any novel feature of construction or operation or novel combination of parts present in the embodiment of the invention described and shown in the accompanying drawing whether within or without the scope of the appended claim and irrespective of other specic statements as to the 2o scope of the invention contained herein.

In the drawing:

Fig. 1 is a vertical side section through the machine with some of the parts diagrammatically indicated.

Fig. 2 is a front view of part of the machine.

By means of the present invention, an extremely light, rapidly acting pneumatic is provided for operating each typewriter key. The typewriter,

with which the pneumatics forming part of the. -3 0' present invention is particularly adapted for use,

. is such as disclosed in Patent-s 1,777,055 and 1,873,512. Briefly, the typewriter has the char-- l acter keys III forming upright parts of horizontal release levers II normally urged upwardly by springs I2. Upon depression of a key I0, its lever Il is rocked clockwise releasing a latch I3 from restraint on a cam I4, permitting a 'spring arm I5 to move the cam against the periphery of a continuously rotating friction sleeve shaft I6.

The cam ls rotated by contact with shaft I6, caus-v ing the carrier I1 of the cam to rock in a direction for depressing a link I8 which through linkage I9 propels the type bar 20 toward the platen 2| to effect printing of the character denoted on the operated key. During the nal.

increment of movement of type bar 20, it strikes a universal bar 22 to actuate the escapement levery 23 for releasing the escapement mechanism to effect a carriage spacing movement.

59 The keys In may be manually operated in the usual manner or may be alternatively automatically operated under control of a perforated sheet S, perforated in accordance with the data to be transcribed by the typewriter. Each character or i element of the typewriter functions under control of a different perforation. yPerforated Sheet S feeds over a tracker bar 25 which has holes 28 each connected by a conduit 21 to a port 28 in a cylinder block 29. 'Ilhe port 2B communicates. with a lower portion of a cylinder 30 in the 5 cylinder block. 'I'he bottom of the cylinder 30 is formed with a guide recess 3| for coacting with and guiding .the lower portionof a pin 32 dependent from a'valve plate 33 which has a loose, completely free sliding engagement with the walls 10 of the cylinder bore 3D. The height of pin 32 is lsuch that the valve plate 33 is located above the port 28.

Above the valve plate 33, cylinder 30 has an' exhaust port 34 connected by a conduit 35 to a vacuum tank 36 in which a vacuum is maintained by a suitable vacuum pump. The upper end of the cylinder-bore 30 is sealed by a thin plate or disk 31 having a central opening through' which a pin 38, extending upwardly from the valve 20 plate 33, passes to the exterior of a cylinder block. Set on the upper end of this pin 38 is a wider cap'39 engaging the lower edge of one arm of a lever 40 intermediately pivoted by a post 4I to the top of the cylinder block 29. The oppo-f 25 site end of lever 40 is connected by a vertical link 42 to lone of the key or releaselevers II.

As long as closedor imperforate portions of record sheet S are-above the individual-holes 26 l in the tracker bar 25, there is a substantial, equal 30 vacuum on the opposite sides of the valve plate `t3.. When a perforation in the record sheet registers with the associated hole 26 in the tracker' bar 2,5, air under atmospheric pressure rushes into connected conduit 21 and through the latter en- 35 ters port 28 of the associated cylinder -bore 3Ilto act on the bottom of valve plate 33. As a result, valve 33 rises rapidly, causing the cap 33 to rock lever 40 clockwise, thereby depressing the link 42 to actuatethe key lever in the same man- 40 ner as though the latter were depressedby a human operato-r. Because of 'depressibn of the release or key lever I I, the'printing or type mechanism corresponding to the sensedor active perforation in the record sheet is coupled. to the .45

power actuator I6 for eiecting the printing of the character corresponding to the said perforation.

as the perforation in sheet S moves beyond its hole 26 in the tracker bar, the flow of air into the port 28 of the connected cylinder 30 stops, and the air remaining in the system is rapidly exhausted through the port 34 into the vacuum tank. As a result, the pressure on both sides of the valve plate again is equalized, and the valve drops to its normal position under the influence of the spring l2 acting through the connected elements Il, 42 and 40 on the valve plate.

It may be noted that in the manual operation of the typewriter keys I0 and levers Il, the links 42 are lowered to rock the intermediate levers clockwise, lifting the left hand ends of the levers freely above the top of the caps 39 of the pneumatic valves 33. Thus, the connections between the pneumatic valves and the keys are such that the keys may be freely operated, with the elements 40 and 42 adding no appreciable resistance to operation of the keys, and without any interference from the pneumatic actuators and without disturbing the positions of the latter. The cylinder blocks 29 are disposed in tiers, one above another, each having a plurality of pneumatics 30-33, arranged below the key levers Il. As may be understood from Fig. 2, the valves 33 of the superposed cylinder blocks are not in the same vertical plane, but are offset horizontally relative to one another so as to locate the caps 39 of the cylinder valves along parallel vertical planes substantially co-extensive with the planes of their associated key levers I I. By staggering the relatively wide valves of the adjacent key levers and locating them at different horizontal levels, the relatively narrow connections from the valves to the adjacent key levers may be disposed as closely as desired next to each other, and also, if desired, maybe connected at the same leverage distance from the fulcrum of each of the key levers. Thus, all of the valves may act with an equal, predetermined leverage on their associated key levers Il.

Due to the automatic power actuation by sleeve I6 of the type linkage, permitting the key levers Il to act simply as release levers for releasing the associated cams for operation by the power actuator I6, or in other words enabling the key levers I l to act simply as clutch coupling elements, the force necessary to depress the key levers is considerably less than when the act of depressing the key must itself provide all the power for propelling the type against the platen. Accordingly, the` individual pneumatics may be relatively small and the valve plates 33 thereof very light and sensitively responsive to differences in pressure acting on the opposite sides thereof so as to rapidly and with a minimum of effort actuate the release levers Il.

It is to be understood that the invention is not restricted to application of the pneumatics to a typewriter keyboard, but may be utilized with any keyboard machine to pneumatically operate the keys thereof. Further, where manual operation of the keyboard is not required, the finger elements or keys I0 may be eliminated from the key or release levers.

While there has been shown and described and pointed out the fundamental novel features of the invention as applied to a single modification, it will be understood that various omissions and substitutionsl and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention therefore to be limited only as indicated by the scope of the following claim.

What is claimed is as follows:

Pneumatic operating means for operating key levers under control of perforations in a recordV sheet passing over a sensing track having sensing holes, comprising a cylinder for each key lever, a valve and a plunger rigidly connected to each other to form ,a unitary structure slidably mounted by the cylinder, with one end of the plunger protruding outside the cylinder, a lever having one moment arm in engagement with the protruding end of the plunger, a 'link connected at one end to the other moment arm of the lever and connected at the other end to the key lever for depressing the latter uponmovement of the plunger during the forward stroke oi' said unitary structure, a direct connecting duct between each sensing hole of the track and a portion of the cylinder at one side of the valve, and a vacuum connection to the cylinder at the opposite sideof the valve, whereby upon registration of a hole on the record sheet with a sensing hole the connecting duct admits air directly to the associated cylinder to slidably actuate the unitary structure for causing depression of the associated key lever.

ALBERT W. MILLS. 

